“If we can understand the principles of energy conversion at this very small scale, we can come up with new energy technologies that may look very different from the ones we have now. “
-Kavli ENSI Founding Director Paul Alivisatos
We know a lot of about how to harness energy from oil, wind, and the motion of water through a dam, and energy has become central to our modern civilizations. Our current energy-generation schemes, however, seem crude in comparison to the elegant systems nature has evolved over millions of years. Those natural systems serve as inspiration for researchers at the Kavli Energy NanoScience Institute (ENSI), who aim to be part of creating powerful new approaches to energy conversion, utilization and efficiency.
The Kavli ENSI is a team of 18 world-class scientists from UC Berkeley and Berkeley Lab from physics, engineering, materials science and engineering. Together, they aim for two complementary goals that inform and build on each other: 1) gain a deeper understanding of how biological molecules capture and convert energy, and 2) engineer nanodevices that mimic and improve on nature’s tricks, using materials ranging from graphene and metal oxide frameworks to nanowires and nanolasers.
Many Kavli ENSI members have worked on nanoscience projects as varied as photosynthesis, nanomachine-enabled virus reproduction, nanotube motors and devices, engineered nanostructures, and ways to manipulate the movement of heat. They often collaborate with their peers, and with researchers in other disciplines. At Kavli ENSI, the nanotube researcher has the opportunity to interact with researchers who work on biological nanomachine motors. Researchers who want to control the flow of heat in nanoscopic devices get to talk with scientists who have faced similar challenges building devices to control the flow of light and electrical charges.
This kind of collaboration is vital to making real change in the way deal with energy. “We’re like a team here,” says Felix Fisher, Professor of Chemistry and an ENSI researcher. “You take inspiration from people working in other areas, and get expertise from many brilliant minds. Only a group of people working together like this can actually address the bigger picture of energy.”
ENERGY AT THE NANOMETER SCALE
Much of today’s energy research focuses on improving well-known technologies, such as batteries, liquid fuels, solar cells and wind generators. On the nanoscale, however, energy is captured, channeled and stored in totally different ways dictated by the quantum mechanical nature of small-scale interactions. Scientist have yet to unravel the foundational issues of how energy is converted to work on that scale.
ENSI researchers are moving toward that goal. Work by UC Berkeley and Berkeley Lab chemist Graham Fleming has shown, for example, that when leaf pigments capture light in the form of photons, electrons are excited and interact in a coherent way not seen at larger scales. This quantum coherence could potentially be incorporated into nanoscale artificial systems to produce energy from sunlight more efficiently.
While studying nanoscale motors inside cells, UC Berkeley physicist Carlos Bustamante and Berkeley Lab theorist Gavin Crooks discovered that energy flow does not always follow the standard rules of macroscopic systems. Nanomotors can sometimes move backward, for example, akin to a ball rolling uphill briefly. Such quantum weirdness confers some real benefits to biological motors, and these benefits might be replicated to create more efficient nanomachines or self-regulating nanoscale energy circuits.
Other Kavli ENSI scientists are investigating how heat flows in nanomaterials and whether the vibrational energy, or phonons, can be channeled to make thermal rectifiers, diodes or transistors analogous to electronic switches in use today; developing novel materials, ranging from polymers to cage structures and nanowires, with unusual nanoscale properties; or designing materials that could sort, count and channel molecules along prescribed paths and over diverse energy landscapes to carry out complex chemical conversions.
THE KAVLI ENSI's RESEARCH IS FOCUSED AROUND SIX THEMES:
Thermal Energy and Circuitry
Thermal energy is all around us in the form of heat, including heat generated by our electronics. That heat, which is essentially lost energy, burdens our electronics and holds us back from advanced electronics functions. The Kavli ENSI envisions creating new switches that may replace the transistor while demanding less energy extending our current cyber capabilities. Read More
Nanoscale Control of Energy Flow
Photosynthesis converts light into easily retrievable energy stored in chemical bonds. Researchers are discovering that the process is more sophisticated than once imagined: plants draw on the quantum nature of light in their feats of capturing energy. The Kavli ENSI seeks to gain a better picture of the quantum mechanics of photosynthesis, and to use custom-designed nanomaterials to harvest light energy and convert it to fuel. Read More
Artificial Energy Conversion and Circuits
Ultimately, Kavli ENSI will harness the principles it discovers to create entire systems and circuits of efficient energy management based on nanoscale components. This means being able not only to generate, but also store and transport energy in ways not currently possible on a societal scale. It also entails taking into account the environmental impact of producing these new technologies. ENSI researchers aim to strike a balance between costs and benefits of new nanoscale approaches, and make new discoveries that contribute to a truly sustainable energy future. Read More
Our bodies are filled with nanomachines that function as molecular motors, converting chemical energy into mechanical work. and that do everything from contract muscles to synthesize and fold proteins into useful shapes. These nanomachines, however, operate within a narrow temperature range, in the midst of energy fluctuations inherent at the nanoscale. The Kavli ENSI aims to discover how nanomotors take advantage of these fluctuations to achieve high thermodynamic efficiencies, and how to combine biological motors with manmade ones to create new, efficient technologies. Read More
Chemical Transformation and Catalysis
Catalysts can speed reactions by orders of magnitude, and lower the energy required. Nature has evolved catalysts for photosynthesis that contain tiny chambers where molecules interact. A major goal of ENSI is to emulate this design in the creation of artificial catalysts that can be used to produce fuel and other complex molecules. Read More
Energy Systems Design
Increasing efficiency requires not only devising new technologies, but also placing these technologies together into systems that can convert one type of energy into another for storage, transport, or immediate use. Scientists at the Kavli ENSI take inspiration from nature’s biological systems, and are working to understand and control energy conversion at the nanoscale. New insights will allow for the construction of whole systems built from different nanoscale components that together accomplish efficient management of energy. Read More